According to an announcement Mrs. Carter posted on Instagram on Thursday (Jan. 31), The Carters want to offer a lifetime's worth of free tickets to their upcoming shows to any fans who can prove that they've switched over to a vegan lifestyle. Reuters reports that Jay-Z pledges to eat at least two plant-based meals a day while his wife promises to eat plant-based breakfasts and go meatless on Mondays.

The contest rules state that one fan will get a pair of tickets to one official concert tour by Jay-Z and/or Beyonce for the next 30 years. Their latest challenge for their fans comes in support of the Greenprint Project, which encourages people to reduce their environmental footprint by eating plant-based meals.

Hov and Beyonce's journey as Vegans has been ongoing for the past five years. The Roc Nation founder first announced his plans to live a vegan lifestyle back in 2014. He embarked on his vegan journey by using a food plan created by the Greenprint Project's founder Marco Borges.

"Psychologists have said it takes 21 days to make or break a habit," Jay-Z said in a letter on Life + Times. "On the 22nd day, you’ve found the way. On December 3rd, one day before my 44th birthday I will embark on a 22 Days challenge to go completely vegan, or as I prefer to call it, plant-based!! This all began a few months back when a good friend and vegan challenged me to embrace a “plant-based breakfast” everyday. It was surprisingly easier on me than I thought."